Hydraulic helmet

ABSTRACT

A helmet including an outer resiliently deformable shell, an inner compressible liner contacting the user&#39;&#39;s head, and an intermediate portion positioned between the shell and liner including a hydraulic cushioning assembly. The assembly includes a plurality of spaced elastic cells and an elastic sump generally coextensive with the interior of the shell and means connecting some of the cells to other of the cells and/or to the sump for intercommunication of the hydraulic fluid therebetween. The connecting means includes constrictive passageways to restrict the fluid flow therethrough. The interaction of the deformable shell hydraulic assembly and compressible liner results in the dissipation, absorption and distribution of the energy of an external blow delivered to the shell.

United States Patent [72] Inventors James R. Cade;

Brady ll. Gmthouse, both of Gainesville,

Fla. [2| Appl No. 808,559 [22] Filec Mar. 19.1969 [45] Patented Aug. 24, I971 [73) Assignee Hop-N-Gator, lnc.

Tallahassee, Ba.

[54] HYDRAULIC HELMET 25 Claims, 4 Drawing Figs.

[52] U.S. Cl. 2/3 [SI] A42b 1/08 [50] FieldotSearch 0 213.6

[56] Relerences Cited UNITED STATES PATENTS 1618.780 ll/l9S2 Cushman 2/3 2.664.567 lll954 Nichols 2/3 3,039.l09 6/l962 Simpson.... 2/3 3.186.004 6/1965 Carlini .r 2/3 Primary ExaminerAlfred R. Guest Attorneys-George H. Baldwin and Arthur G. Yeager ABSTRACT: A helmet including an outer resiliently deformable shell, an inner compressible liner contacting the user's head, and an intermediate portion positioned between the shell and liner including a hydraulic cushioning assembly. The assembly includes a plurality of spaced elastic cells and an elastic sump generally coextensive with the interior of the shell and means connecting some of the cells to other of the cells and/or to the sump for intercommunication of the hydraulic fluid therebetween. The connecting means includes constrictive passageways to restrict the fluid flow therethrough. The interaction of the deformable shell hydraulic assembly and compressible liner results in the dissipation, absorption and distribution of the energy of an external blow delivered to the shell.

PATENTEU AUG24 Ian INVENTORS James A. can: By Brady 3. Grmffiause 7 ,4'rramvir HYDRAULIC HELMET BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to an improved hat or helmet, and more particularly to a football or crash helmet designed to combine lightweight with a high degree of protection against relatively slow, nonballistic impact. In more specific detail, the invention disclosed herein pertains to helmets having a hydraulic cushioning assembly for use in protecting sportsmen, aviators, vehicle racers, workmen, and the like wearing such helmets, against impact or shock and possible damage resulting therefrom when the helmet is struck by a heavy blow or external force. The helmet specifically affords substantial protection to the top, front, rear, and sides of the head of the user thereof and is additionally light in weight and comfortable to wear.

2. Description of the Prior Art Helmets have heretofore been lines with resilient padding material such as leather, suspended strapping, foam rubber and the like for the purpose of cushioning against shock and impact. However, these materials have not proved entirely satisfactory since they readily yield under impact, thereby providing practically no significant protection after a predetermined degree of yielding of the liner Attempts have been made to overcome this disadvantage by providing cellular rigid but crushable liners which would compress and rupture or crumble eventually under severe shock, but these have not been found to be entirely satisfactory, because the liner is destroyed on impact. The helmet then becomes useless for cushioning or protecting against repeated impacts without rebuilding or reconditioning same.

In addition, impact protection in helmets heretofore has been provided largely by the use of heavy padding in combination with rigid outer shells constructed from materials such as rigid plastic, fiberglass or steel. However, in such prior art devices, the direction of the blow or impact has been substantially unchanged and no attempt has been made to deflect this blow or its path of travel so that it will dissipate its force or energy in directions generally parallel to the outer surface of the helmet.

Helmets, safety has and other like devices have been previously devised, such prior art devices being generally disclosed in U.S. Pat. Nos. 1,348,950, 1,833,708, 2,239,946, 2,618,780, 2,664,567, 2,759,186, 2,768,919, 3,039,109, 3,070,802, 3,186,004, 3,254,883, and 3,283,349. Applicant's invention of an improved safety helmet including a hydraulic cushioning assembly, disclosed herein, is an improvement over such prior art devices and generally alleviates the aforementioned problems and difficulties of the prior art.

SUMMARY OF THE INVENTION A general object of this invention is to provide a liner construction for helmets, such as used by football players, vehicle racers, pilots, construction workmen and the like for protection against impacts and blows and the like which will provide an extremely high degree of comfort and wear and an extremely high degree of protection against such impacts and blows to substantially protect the person wearing such helmet.

Another object of the invention is to provide an improved helmet having a liner which includes the hydraulic cushioning assembly for protecting the head of the wearer of the helmet against impact or shock and possible damage resulting therefrom when the helmet is struck by a heavy blow or other external force.

Yet another object of the subject invention is to provide an improved helmet having an inner lining including an expansible hydraulic cushioning assembly and a compressible liner in contact with the user's head wherein an expansion of the assembly causes compression of the liner which further protects the users head.

Still a further object of the instant invention is to provide an improved helmet having a resiliently deformable shell wherein the force or energy of a blow or impact delivered to the helmet is dissipated in directions generally parallel to the outer sur face of the helmet and distributed substantially over the entire area of contact with the user's head.

Yet a further object of this invention is to provide an improved helmet which includes a hydraulic cushioning assembly within the helmet and is so constructed that the expansion of the cushioning assembly will be substantially in directions generally parallel to the outer shell of the helmet to provide an effective shock or impact dissipating and absorbing means for protecting the head for the wearer.

In general these objects are obtained by providing the helmet including an outer resiliently deformable shell portion generally conforming to the shape of the head of a user, an inner compressible liner portion for contacting the head of the user and an intermediate portion positioned between the shell and liner portions. The intermediate portion includes a hydraulic cushioning assembly having a plurality of spaced cells extending generally coextensive with the top, front, rear and sides of the shell portion with means connecting some of the cells to other of the cells for intercommunication of the fluid between some of the cells. The connecting means includes constrictive passageways extending between some and other of the cells to permit restricted flow of the fluid between the cells to dissipate and absorb the energy of a blow delivered to the shell portion of the helmet.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of the improved hydraulic helmet of this invention;

FIG. 2 is a top plan view of the hydraulic assembly of the helmet with the same laid out flat in a single plane;

FIG. 3 is a transverse sectional view taken along line 3-3 of FIG. 2; and

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With detailed reference to the drawings now, and in particular to FIGS. 1 and 4 thereof, the improved hydraulic helmet ll] of this invention is seen to include an outer or shell portion 12, an inner or liner portion 14 and a middle or intermediate portion 15, including a hydraulic assembly 16. Helmet 10 further includes material forming an edging l8 thereabout which is attached to the inner side of shell portion 12 and the inner side of liner portion 14 and overlapping liner 4 and middle portions 14 and 15 of the helmet along the edges thereof. The usual chin strap 20 is provided attached to the shell portion 12 of the helmet l0 and includes a left portion 22 and a right portion 24 which are respectively attached to helmet by appropriate fastening means at 26 and 28.

Shell portion 12 is designed to generally conform to the shape of the head, as seen in FIGS. 1 and 4, and includes a small opening 30 extending therethrough generally at the center of the top portion 31 thereof, the purpose and function of which will be explained more fully hereinbclow. Shell portion 12 is made from a material such that the same is deformable when struck, for example, by a hard or sharp blow or a forceful external impact. Shell portion 12 will deform under the force of the impact or blow, but is resilient and will return to its original shape upon dissipation of the energy of the impact or blow delivered thereto. It has been found that suitable materials from which to construct shell portion 12 are highdensity polyethylene or a combination of polyethylene and butyl rubber in various amounts, but preferably in a 70230 percent combination of each of these materials respectively. The thickness of the shell portion 12 should be sufficient to provide a hard, firm and protective cover and should be in the nature of three-sixteenths of an inch in thickness or greater.

With particular reference to FIG. 4, the liner portion 14 which is connected to the immediate or middle portion by appropriate glue or cement covers substantially all of the interior portion of the helmet except for the extreme lower side portions where the chin strap is attached. This liner portion i4 is a layer of sponge or sponge rubber and preferably is about one-half inch in thickness or greater. It has been found advantageous to construct liner portion 14 from a closed cell butyl rubber sponge which is 50 percent compressible. Attached to the lower outer edge of the sponge material and completely surrounding the helmet is the inner edge portion of material or edging 18 which may be formed from a leather or plastic product and which is attached thereto by cement, stitching or other appropriate means.

Positioned between shell portion 12 and the liner portion 14 is the intermediate portion 15 including the hydraulic assembly or cushioning system 16 which is attached by appropriate gluing or cementing to outer portion 12. As can be clearly seen in FIGS. 2 and 3, hydraulic assembly 16 of intermediate portion 15 includes a centrally disposed sump or reservoir 32 which is positioned adjacent the top central portion 31 of shell 12 of the helmet. Positioned within sump 32 and extending therethrough is a valve 34 by which the hydraulic assembly 16 may be filled with a hydraulic fluid. Valve 34 extends upward through a small opening 30 within shell portion I2 of the helmet, permitting access to the hydraulic arrangement from a position exterially of the helmet. If found desirable, a small rubber plug or the like may be provided to nestingly fit within opening 30 and extend over and cover valve 34 such as to make the outer shell 12 of helmet 10 substantially continuous. if desired, valve 34 of hydraulic assembly 16 could be located in and through a small opening within the lower back section of shell portion 12 of the helmet, and in this position valve 34 would be connected to and communicate with the interior of cell 86 or another rear cell, providing means for filling hydraulic assembly 16 with a hydraulic fluid.

Attached to sump 32 and extending outward therefrom in a somewhat radial fashion are a plurality of bag members or cells 36. Cells 36 are arranged in groups or sets which when properly positioned and secured within outer portion 12 of helmet 10 include a front set 38 which covers and protects part of the top and the forward portion of the uses 5 head, a left side set 40 which covers and protects part of the top and the left side portion of user's head, a rear set 42 which covers and protects part of the top and the rearward or back portion of the user's head, and a right side set 44 which covers and protects part of the top and the right side portion of the user's head. The radially extending bag members 36 are interconnected with and communicate with sump 32 while other bag members 36 are interconnected with and communicate with the radially extending bag members by means of passageway or constrictions, as at 46.

Group or set 38 includes three cells 48, 50 and 52 connected to sump 32 and extending generally outward therefrom in a radiallike manner and a fourth cell 54 extending transversely across the outer ends of cells 48 through 52 and connected thereto. Cell 48 communicates with the interior of sump 32 by passageway 56 and the interior ofcell 54 by means of constriction or passageway 58, and cell 52 communicates with the interior of cell 54 by means of passageway 60 and the interior of sump 32 by means of passageway 62. Cell 50 does not communicate with the interior or cell 54. but is open to the interior of sump 32 by means of constriction or passageway 64.

The left side group 40 of hydraulic arrangement 16 includes a pair of longitudinally extending cells 66 and 68 connected to sump 32 at one of each of their ends and a third cell 70 connected to the other ends of cells 66 and 68 and extending transversely thereacross. Cell 66 communicates with the interior of cell 70 by means of passageway 72 and the interior of sump 32 by means of passageway 74, and cell 68 communicates with the interior of sump 32 by means of passageway 76 and is open to the interior of cell 70 through passageway 78.

Rear grouping or set 42 which protects the back or rear portion of the user's head includes three cells 80, 82 and 84 which are connected to sump 32 and extend outward therefrom in a radial manner, and a fourth cell 86 connected to the opposite ends of cells through 84 and extending transversely thereacross. Sump 32 communicates with cells 80, 82 and 84 by means of respective passageways or openings 88, 90 and 92, and the interior of cell or bag member 86 is open to the interior of cells 80 and 84 by respective passageways 94 and 96. Cell 82 is connected to bag member 86 but does not communicates therewith.

Right side group or set of cells 44 which cover and protect the right side portions of the user's head includes a pair of laterally extending cells 98 and 100 attached to sump 32 and a third bag member or cell 102 connected to the opposite ends of cells 98 and 100 and extending transversely thereof. The interior of bag member or cell 98 communicates with the interior of sump 32 through opening or passageway 104 and the interior of cell 102 through passageway 106, while cell 100 com municates with sump 32 by means of passageway [08 and cell 102 by means of passageway 110.

The cells or bag members 36 which make up the hydraulic assembly 16 of the helmet are preferably made from Neopreme which is fairly elastic such that these bags or cells may become stretched to dissipate the energy of an impact or blow on the helmet. The individual cells or bag members are each preferably of a width or diameter of between one-half to threefourths of an inch and of such length to properly protect substantially all portions of the user's head when placed within the helmet, and further of a length such that the total area of the interior of shell portion 12 of the helmet covered by hydraulic assembly [6, including the sump and the individual cells or bag members, is preferably between one-half to two thirds of the total available area of the interior of the helmet shell. The size of the passageway or constrictions, as at 46, between the cells and the sump and between the interconnected cells is related to the viscosity of the hydraulic fluid and the elasticity of the cells, but is preferably of a diameter of between one-sixteenth inch and three-sixteenth inch. in addition, the length of the constrictions or passageways, as at 46, is related to the amount of resistance or impedance set up to the flow of the hydraulic fluid in the hydraulic assembly 16. The length of the passageways shown in the drawing are approximately one-sixteenth to one-eighth of an inch, but could range upward therefrom to about three-fourths of an inch in dimension. In this connection, thin-walled tubes of varying lengths up to three-fourths of an inch, could be positioned through and sealed in the passageways.

The hydraulic assembly 16 including the sump and cells of the helmet if filled through the valve 34 positioned in and through the top central portion 31 of the helmet with a viscous fluid, preferably olive oil. Other fluids which could be used in the hydraulic assembly of the helmet include, but are not limited to, castor oil, safflower oil, glycerin, a heavy weight motor oil, and a combination of glycerin, water and ethanol. The filling is preferably completed after the particular sized helmet is placed on the user's head to insure a proper fit for the user thereof, and the filling of the hydraulic assembly is preferably continued until there is a slight pressure of about 5 to 7 millimeters of mercury. If the helmet then fits too loosely, the amount of hydraulic fluid could be increased to cause the helmet to fit the user's head in the correct manner.

When fitting the hydraulic helmet of this invention upon the head of a user, the hydraulic assembly 16, shown particularly in FIGS. 2 and 3, is filled with olive oil or the like until the same is under a slight pressure. The helmet can be fitted to various head sizes of different users thereof by slightly increasing or decreasing the thickness of the liner portion 14 and also by slightly increasing or decreasing the amount of fluid contained within the hydraulic system 16 of the intermediate portion 15 of the helmet.

When the head of a person using and wearing the helmet of this invention, is hit or struck by a blow or receives an impact, the energy from such impact is absorbed and/or dissipated first by the shell portion 12 which deforms under such impact, secondly by the hydraulic assembly 16 and thirdly by cornpressing the rubber sponge of the liner 14. The energy of the impact or blow 'is absorbed and dissipated primarily by the hydraulic'assembly wherein the hydraulic fluid, e.g. olive oil, flows from the partially collapsed cell or cells directly beneath the blow or impact or below the deformed portion of the shell portion 12 through the constrictions into the sump and adjacent cells expanding same. This flow or movement of the hydraulic fluid from the partially collapsed cell or cells located under the impact into the other adjoining and adjacent cells and sump along with the expansion of the same absorbs and dissipates the energy of the blow or impact imparted to outer shell 12 of the helmet 10. In effect, the whole helmet moves a little with the blow so that as the cells under the impact are emptying, the other adjacent cells expand as fluid enters same from the cells that are emptying and/or from the increased fluid in the sump. The impact on the shell portion 12 is dissipated or absorbed in that the force of the impact performs work prior to being transmitted to the head of the user of the helmet. Work is performed by defonning the outer shell portion 12, by movement of the hydraulic fluid through constrictions, by expanding the adjacent cells not under the deformed portion of shell portion 12 and/or expanding the sump (if the sump is beneath the impact, the sump partially collapses and thecells expand-assuming a sufficient impact), and by the compressing of liner 14. Not only is the force absorbed and/or dissipated, but the resulting force is distributed generally throughout the entire area of the head resulting in lesser damage to the head of the user than has been experienced with prior commercial helmets.

While only a certain preferred embodiment of this invention has been shown and described by way of illustration many modifications within true spirit and scope of this invention and withinfthe following-claims will occur to those skilled in theiirt Weclaini:

l. A safety helmet comprising an outer shell portion designed. to generally conform to the shape of the head of a user. an inner compressible liner portion for contacting the head. of the user, and an intermediate portion positioned between said shell and liner portions, said intermediate portion including a hydraulic cushioning assembly containing hydraulic liquid, said assembly includinga plurality of spaced and expandable cells extending generally coextensive with the top, front, rear and sides of said shell portion, means for connecting some of said cells to other said cells for interoommunication of hydraulic liquid between said some and other cells, said means including constrictive passageways extending between said some and other cells to permit restricted flow of the hydraulic liquid between said cells to dissipate and absorb the eneigy of a blow delivered to said shell portion of the helmet, said liner portion compression between the user's head and said hydraulic assembly generally beneath the location of the blow on said shell portion to cause the liquid contained within said assembly to flow out of said cells positioned generally beneath the blow and into said cells adjacent thereto.

2. In the safety helmet as defined in claim 1 wherein said hydraulic assembly further includes a hydraulic sump posibeing connected to said sump and extending generally outwardly therefrom toward the front, rear and sides of said shell portion.

3. ln a safety helmet as defined in claim 2 further comprising valve means connected to said sump and communicating with the interior thereof whereby said assembly may be filled with hydraulic liquid through said valve means.

4. In the safety helmet as defined in claim I further comprising a valve means connected to said assembly and communicating with he interior thereof whereby hydraulic liquid may be inserted through said valve means and into said assembly.

5. in the safety helmet as defined in claim I wherein said hydraulic assembly extends over and occupies at least one-half of the available space existing between said shell portion and said inner liner portion,

6. In the safety helmet as defined in claim I wherein said hydraulic assembly contains hydraulic liquid under pressure thereby insuring hydraulic liquid throughout said assembly.

7. In the safety helmet as defined in claim 1 wherein said cells are elastic and said hydraulic assembly is substantially completely filled with hydraulic liquid.

8 In the safety helmet as defined in claim 7 wherein said hydraulic assembly contains hydraulic liquid under pressure thereby insuring hydraulic liquid throughout said assembly,

9. in the safety helmet as defined in claim I wherein said cells are between about one-half and about three-fourths of an inch in diameter and wherein said inner compressible liner portion is about one-half of an inch in thickness.

10. in the safety helmet ad defined in claim I wherein said constrictive passageways are between about one-sixteenth and three-sixteenth of an inch in diameter.

11. In the safety helmet as defined in claim 1 wherein said outer shell portion is resiliently deformable, said shell portion deforming under the impact of the blow to transmit the'energy of the blow to said hydraulic assembly causing the liquid contained therein to flow out of said cellspositioned generally beneath the blow and into said cells adjacent thereto.

12. A safety helmet comprising an outerresiliently defonnable shell portion designed to generally conform to the shape of the head of user and an inner portion including .a hydraulic cushioning assembly containing hydraulic liquid under s pressure above atmospheric thereby insuring hydraulic liquid throughout said assembly, said assembly being attached to said shell portion, said assembly including a plurality of spaced and expandable cells generally coextensive with the top, front, rear and sides of said shell portion, means for connecting some of said cells to other said; cells for fltercommunieation of hydraulic liquid between said some and other cells, solid means including constrictive passageways extending between on some and other cells to permit restricted flow of the hydraulic liquid between said cells todissip'ste and absorb the energy of a blow delivered to said deformable shell portion of the helmet, said shell portion deforming under the impact of the blow to transmit the energy of the blow to said hydraulic assembly causing the liquid contained therein to flow out of said cells positioned generally beneath the blow and into said cells sdjacent thereto.

13. In the safety helmet as defined in claim [2 wherein said hydraulic assembly further includes a hydraulic sump positioned adjacent the top of said outer shell portion, some of said cells being connected to said sump and extending generally outwardly therefrom toward the'front, rear and sides of said shell portion.

14. In the safety helmet as defined in claim 12 further comprising valve means connected to said hydraulic assembly and communicating with the interior thereof whereby hydraulic liquid may be inserted through said valve means and into said assembly.

15. A safety helmet comprising an outer resiliently deformable shell portion designed to generally conform to the-shspeot the head ofa user, an inner compressible liner portion for contscting the head of the user, and an intermediate portion positioned adjacent the top of said shell portion, some of said cells tioned between said shell and liner portions, said 'intermedlate portion including a hydraulic cushioning assembly containing hydraulic liquid to dissipate and absorb the energy of a blow delivered to said shell portion of the helmet, said liner portion compressing between the user's head and said hydraulic assembly generally beneath the location of the blow on said shell portion to cause liquid contained within said assembly to flow out of portions thereof positioned generally beneath the blow and into other adjacent portions thereof, said shell portion deforming under the impact of the blow to transmit the energy of the blow of said hydraulic assembly causing the liquid contained therein to flow out of portions thereof positioned generally beneath the blow and into other adjacent portions thereof.

16. in the safety helmet as defined in claim is further comprising a valve means connected to said assembly and commu nicating with the interior thereof whereby hydraulic liquid may be inserted through said valve means and into said assembly.

17. In the safety helmet as defined in claim l wherein said hydraulic assembly contains hydraulic liquid under pressure thereby insuring hydraulicliquid throughout said assembly.

18. In the safety helmet as defined in claim wherein said portions of said hydraulic assembly are elastic and said hydraulic assembly is substantially completely filled with hydraulic liquid.

19. In the safety helmet as defined in claim 18 wherein said hydraulic assembly contains hydraulic liquid under pressure thereby insuring hydraulic liquid throughout said assembly.

20. In the safety helmet as defined in claim 15 wherein said hydraulic assembly includes a plurality of cells and a sump with the sump being positioned adjacent the top of said shell portion, some of said cells being connected to said sump and extending generally outwardly therefrom toward the front, rear and sides of said shell portion.

21. In a safety helmet having an outer shell portion designed to generally conform to the shape of the head of user, the im provement comprising an inner portion of expandable material including a hydraulic cushioning assembly containing hydraulic liquid under a pressure above atmospheric thereby insuring hydraulic liquid throughout said assembly, said assembly being attached to said shell portion, said assembly including a hydraulic fluid sump positioned adjacent the top of said shell portion, a plurality of spaced elongated cells connected to said sump and extending generally radially outwardly therefrom toward the front, rear and side edges of said shell portion, additional elongated cells connected to the outer ends of said radially extending cells 'and positioned transversely thereof adjacent the front, rear and side edges of said shell portion, means including constrictive passageways extending between said sump and said radially extending cells and between said transversely extending cells and some of said radially extending cells to restrict the flow of the hydraulic liquid between said sump and cells to dissipate and absorb the energy of a blow delivered to said shell portion of the helmet.

22. in the safety helmet as defined in claim 21 wherein the outer shell portion is resiliently deformable, said shell portion deforming under the impact of the blow to transmit the energy of the blow to said hydraulic assembly causing the liquid contained therein to flow through said passageways generally out wardly from beneath the blow.

23. in the safety helmet as defined in claim 13 further comprising valve means connected to said sump and communicating with the interior thereof whereby hydraulic liquid may be inserted through said valve means and into said sump.

24. A safety helmet comprising an outer resiliently deformable shell portion designed to generally confonn to the shape of the head of a user and an inner portion including a hydraulic cushioning assembly containing hydraulic liquid attached to said shell portion, said assembly including a plurality of spaced and expandable cells generally coextensive with the top, front, rear and sides of said shell portion, means for connecting some of said cells to other said cells for intercommunication of hydraulic liquid between said some and other cells, said means including constrictive passageways extending between said some and other cells to permit restricted flow of the hydraulic liquid between said cells to dissipate and absorb the energy of a blow delivered to said deformable shell portion of the helmet, said shell portion deforming under the impact of the blow to transmit the energy of the blow to said hydraulic assembly causing the liquid contained therein to flow out of said cells positioned generally beneath the blow and into said cells adjacent thereto, said inner portion further including a compressible liner for contacting the head of the user and which is positioned between said hydraulic assembly and the user's head, said compressible liner compressing between the user's head and said hydraulic assembly generally beneath the location of the blow on said shell portion to cause liquid contained within said assembly to flow out of said cells positioned generally beneath the blow and into said cells adjacent thereto.

25. In a safety helmet having an outer shell portion designed to generally conform to the shape of the head of a user, the improvement comprising an inner portion of expandable material including a hydraulic cushioning assembly containing hydraulic liquid and attached to said shell portion, said as sembly including a hydraulic fluid sump positioned adjacent the top of said shell portion, a plurality of spaced elongated cells connected to said sump and extending generally radially outwardly therefrom toward the front, rear and side edges of said shell portion, additional elongated cells connected to the outer ends of said radially extending cells and positioned transversely thereof adjacent the front, rear and side edges of said shell portion, means including constrictive passageways extending between said sump and said radially extending cells and between sald transversely extending cells and some of said radially extending cells to restrict the flow of the hydraulic liquid between said sump and cells to dissipate and absorb the energy of a blow delivered to said shell portion of the helmet, said inner portion further including a compressible liner for contacting the head of the user and which is positioned between said hydraulic assembly and the user's head, said compressible liner compressing between the user's head and said hydraulic assembly generally beneath the location of the blow on the said shell portion to cause liquid contained within said assembly to flow through said passageways generally outwardly from beneath the blow. 

1. A safety helmet comprising an outer shell portion designed to generally conform to the shape of the head of a user, an inner compressible liner portion for contacting the head of the user, and an intermediate portion positioned between said shell and liner portions, said intermediate portion including a hydraulic cushioning assembly containing hydraulic liquid, said assembly including a plurality of spaced and expandable cells extending generally coextensive with the top, front, rear and sides of said shell portion, means for connecting some of said cells to other said cells for intercommunication of hydraulic liquid between said some and other cells, said means including constrictive passageways extending between said some and other cells to permit restricted flow of the hydraulic liquid between said cells to dissipate and absorb the energy of a blow delivered to said shell portion of the helmet, said liner portion compression between the user''s head and said hydraulic assembly generally beneath the location of the blow on said shell portion to cause the liquid contained within said assembly to flow out of said cells positioned generally beneath the blow and into said cells adjacent thereto.
 2. In the safety helmet as defined in claim 1 wherein said hydraulic assembly further includes a hydraulic sump positioned adjacent the top of said shell portion, some of said cells being connected to said sump and extending generally outwardly therefrom toward the front, rear and sides of said shell portion.
 3. In a safety helmet as defined in claim 2 further comprising valve means connected to said sump and communicating with the interior thereof whereby said assembly may be filled with hydraulic liquid through said valve means.
 4. In the safety helmet as defined in claim 1 further comprising a valve means connected to said assembly and communicating with he interior thereof whereby hydraulic liquid may be inserted through said valve means and into said assembly.
 5. In the safety helmet as defined in claim 1 wherein said hydraulic assembly extends over and occupies at least one-half of the available space existing between said shell portion and said inner liner portion.
 6. In the safety helmet as defined in claim 1 wherein said hydraulic assembly contains hydraulic liquid under pressure thereby insuring hydraulic liquid throughout said assembly.
 7. In the safety helmet as defined in claim 1 wherein said cells are elastic and said hydraulic assembly is substantially completely filled with hydraulic liquid.
 8. In the safety helmet as defined in claim 7 wherein said hydraulic assembly contains hydraulic liquid under pressure thereby insuring hydraulic liquid throughout said assembly.
 9. In the safety helmet as defined in claim 1 wherein said cells are between about one-half and about three-fourths of an inch in diameter and wherein said inner compressible liner portion is about one-half of an inch in thickness.
 10. In the safety helmet ad defined in claim 1 wherein said constrictive passageways are between about one-sixteenth and three-sixteenth of an inch in diameter.
 11. In the safety helmet as defined in claim 1 wherein said outer shell portion is resiliently deformable, said shell portion deforming under the impact of the blow to transmit the energy of the blow to said hydraulic assembly causing the liquid contained therein to flow out of said cells positioned generally beneath the blow and into said cells adjacent thereto.
 12. A safety helmet comprising an outer resiliently deformable shell portion designed to generally conform to the shape of the head of user and an inner portion including a hydraulic cushioning assembly containing hydraulic liquid under a pressure above atmospheric thereby insuring hydraulic liquid throughout said assembly, said assembly being attached to said shell portion, said assembly including a plurality of spaced and expandable cells generally coextensive with the top, front, rear and sides of said shell portion, means for connecting some of said cells to other said cells for intercommunication of hydraulic liquid between said some and other cells, said means including constrictive passageways extending between said some and other cells to permit restricted flow of the hydraulic liquid between said cells to dissipate and absorb the energy of a blow delivered to said deformable shell portion of the helmet, said shell portion deforming under the impact of the blow to transmit the energy of the blow to said hydraulic assembly causing the liquid contained therein to flow out of said cells positioned generally beneath the blow and into said cells adjacent thereto.
 13. In the safety helmet as defined in claim 12 wherein said hydraulic assembly further includes a hydraulic sump positioned adjacent the top of said outer shell portion, some of said cells being connected to said sump and extending generally outwardly therefrom toward the front, rear and sides of said shell portion.
 14. In the safety helmet as defined in claim 12 further comprising valve means connected to said hydraulic assembly and communicating with the interior thereof whereby hydraulic liquid may be inserted through said valve means and into said assembly.
 15. A safety helmet comprising an outer resiliently deformable shell portion designed to generally conform to the shape of the head of a user, an inner compressible liner portion for contacting the head of the user, and an intermediate portion positioned between said shell and liner portions, said intermediate portion including a hydraulic cushioning assembly containing hydraulic liquid to dissipate and absorb the energy of a blow delivered to said shell portion of the helmet, said liner portion compressing between the user''s head and said hydraulic assembly generally beneath the location of the blow on said shell portion to cause liquid contained within said assembly to flow out of portions thereof positioned generally beneath the blow and into other adjacent portions thereof, said shell portion deforming under the impact of the blow to transmit the energy of the blow of said hydraulic assembly causing the liquid contained therein to flow out of portions thereof positioned generally beneath the blow and into other adjacent portions thereof.
 16. In the safety helmet as defined in claim 15 further comprising a valve means connected to said assembly and communicating with the interior thereof whereby hydraulic liquid may be inserted through said valve means and into said assembly.
 17. In the safety helmet as defined in claim 15 wherein said hydraulic assembly contains hydraulic liquid under pressure thereby insuring hydraulic liquid throughout said assembly.
 18. In the safety helmet as defined in claim 15 wherein said portions of said hydraulic assembly are elastic and said hydraulic assembly is substantially completely filled with hydraulic liquid.
 19. In the safety helmet as defined in claim 18 wherein said hydraulic assembly contains hydraulic liquid under pressure thereby insuring hydraulic liquid throughout said assembly.
 20. In the safety helmet as defined in claim 15 wherein said hydraulic assembly includes a plurality of cells and a sump with the sump being positioned adjacent the top of said shell portion, some of said cells being connected to said sump and extending generally outwardly therefrom toward the front, rear and sides of said shell portion.
 21. In a safety helmet havIng an outer shell portion designed to generally conform to the shape of the head of user, the improvement comprising an inner portion of expandable material including a hydraulic cushioning assembly containing hydraulic liquid under a pressure above atmospheric thereby insuring hydraulic liquid throughout said assembly, said assembly being attached to said shell portion, said assembly including a hydraulic fluid sump positioned adjacent the top of said shell portion, a plurality of spaced elongated cells connected to said sump and extending generally radially outwardly therefrom toward the front, rear and side edges of said shell portion, additional elongated cells connected to the outer ends of said radially extending cells and positioned transversely thereof adjacent the front, rear and side edges of said shell portion, means including constrictive passageways extending between said sump and said radially extending cells and between said transversely extending cells and some of said radially extending cells to restrict the flow of the hydraulic liquid between said sump and cells to dissipate and absorb the energy of a blow delivered to said shell portion of the helmet.
 22. In the safety helmet as defined in claim 21 wherein the outer shell portion is resiliently deformable, said shell portion deforming under the impact of the blow to transmit the energy of the blow to said hydraulic assembly causing the liquid contained therein to flow through said passageways generally outwardly from beneath the blow.
 23. In the safety helmet as defined in claim 13 further comprising valve means connected to said sump and communicating with the interior thereof whereby hydraulic liquid may be inserted through said valve means and into said sump.
 24. A safety helmet comprising an outer resiliently deformable shell portion designed to generally conform to the shape of the head of a user and an inner portion including a hydraulic cushioning assembly containing hydraulic liquid attached to said shell portion, said assembly including a plurality of spaced and expandable cells generally coextensive with the top, front, rear and sides of said shell portion, means for connecting some of said cells to other said cells for intercommunication of hydraulic liquid between said some and other cells, said means including constrictive passageways extending between said some and other cells to permit restricted flow of the hydraulic liquid between said cells to dissipate and absorb the energy of a blow delivered to said deformable shell portion of the helmet, said shell portion deforming under the impact of the blow to transmit the energy of the blow to said hydraulic assembly causing the liquid contained therein to flow out of said cells positioned generally beneath the blow and into said cells adjacent thereto, said inner portion further including a compressible liner for contacting the head of the user and which is positioned between said hydraulic assembly and the user''s head, said compressible liner compressing between the user''s head and said hydraulic assembly generally beneath the location of the blow on said shell portion to cause liquid contained within said assembly to flow out of said cells positioned generally beneath the blow and into said cells adjacent thereto.
 25. In a safety helmet having an outer shell portion designed to generally conform to the shape of the head of a user, the improvement comprising an inner portion of expandable material including a hydraulic cushioning assembly containing hydraulic liquid and attached to said shell portion, said assembly including a hydraulic fluid sump positioned adjacent the top of said shell portion, a plurality of spaced elongated cells connected to said sump and extending generally radially outwardly therefrom toward the front, rear and side edges of said shell portion, additional elongated cells connected to the outer ends of said radially extending cells and positioned transversely thereof adjacent the front, rear and Side edges of said shell portion, means including constrictive passageways extending between said sump and said radially extending cells and between saId transversely extending cells and some of said radially extending cells to restrict the flow of the hydraulic liquid between said sump and cells to dissipate and absorb the energy of a blow delivered to said shell portion of the helmet, said inner portion further including a compressible liner for contacting the head of the user and which is positioned between said hydraulic assembly and the user''s head, said compressible liner compressing between the user''s head and said hydraulic assembly generally beneath the location of the blow on the said shell portion to cause liquid contained within said assembly to flow through said passageways generally outwardly from beneath the blow. 